Radionuclide cineangiography and Thallium perfusion scanning both are known to be sensitive indicators of the presence of coronary artery disease. We employed both techniques in patients with known or suspected coronary artery disease to permit comparison of the accuracy of the two techniques in the diagnosis of coronary artery disease. We found that both radionuclide cineangiography and perfusion scanning with T1201 are sensitive in diagnosis of coronary artery disease, but radionuclide cineangiography also offers potentially valuable quantitative assessment of functional severity of coronary artery disease.